The present invention relates generally to continuous wave gas ion lasers and more particularly to a power efficient continuous wave gas ion laser system and associated laser tube. The invention is particularly well suited for improving gas ion laser performance in the instance of a fixed level of available electrical input power. An associated method is also disclosed.
Continuous discharge gas ion lasers are relatively inefficient with regard to the use of electrical input power. It should be appreciated that, for this reason, the maximum light output power of such lasers has traditionally been limited, at least in part, by available electrical input power. For example, a typical 120 Volt AC electrical outlet in the United States is rated to provide approximately 17 amps on a continuous basis. As will be seen below, several considerations must be kept in mind when implementing a laser under such an input power constraint.
One factor which relates directly to input power limitations resides in the fact that the input current that is required to maintain a fixed light output from a gas ion laser tube increases in a known way as the tube ages. Hence, the lifetime of the tube is reached when the current drawn by the tube, via a typical laser power supply, meets or exceeds the level of current which is available from the source. In the example of a typical US 120 Volt AC outlet, for a nominal voltage of 106 VAC at a current of 17.3 amps (slightly above the recommended current limit), the end of life power consumption value of a laser tube is therefore just over 1,830 watts.
Based on a particular constraining value of input electrical power, it should be appreciated that the light output of a particular laser tube may be increased by driving the tube at higher current levels. However, the increase in output power, in this instance, is achieved by sacrificing a significant portion of the lifetime of the tube, as compared with driving the tube at a lower rated current level. In other words, by driving the tube at a current level which is higher than its rated level the end of life power consumption value will be reached in a proportionately shortened period of time.
The present invention discloses a system, laser tube and associated method which provide a highly advantageous improvement in output power in view of a particular constraining value of input electrical power or, alternatively, a highly advantageous improvement in laser tube lifetime.